New preparation of 1,1,2,2-tetrafluoro-2-(trifluoroethenyloxy)-ethanesulfonyl fluoride

A new preparation method of 1,1,2,2-tetrafluoro-2-(trifluoroethenyloxy)-ethanesulfonyl fluoride (8) has been developed utilizing the unique performance of the imidazole protective group. Namely, the electrodonating character of the imidazole protective group on the sulfonyl group enables the formation of the novel intermediate monomer, which can be easily converted to 8 by the reaction with HF.